Recently, in the fields of laser processing and large capacity storage, near-field light has come to be used to achieve microfabrication and high-density recording, etc., which have conventionally been impossible due to light diffraction limit. A near-field light output device configured to output near-field light directs laser light to an optical waveguide where a near-field light generating element is disposed, and outputs near-field light generated by the near-field light generating element to irradiate a desired area with the near-field light.
In thermally-assisted magnetic recording in which high-density recording is performed by using near-field light, a magnetic recording medium made of a magnetic material having a large magnetically anisotropic energy is used for a more stable magnetization. And a portion of the magnetic recording medium where data is to be written is heated by using the near-field light, to thereby reduce the anisotropic magnetic field of the portion, and immediately thereafter, a writing magnetic field is applied to the portion, and thereby minute-size writing is performed.
A conventional thermally-assisted magnetic recording head is disclosed in Patent Literature 1 listed below. FIG. 14 is a schematic front view of, and FIG. 15 is a perspective view showing a principal portion of, the conventional thermally-assisted magnetic recording head. The thermally-assisted magnetic recording head 1, which includes a slider 10 and a semiconductor laser element 40, is located over a magnetic disk D.
The slider 10 floats above the magnetic disk D while the magnetic disk D is rotating, and a magnetic recording portion 13 and a magnetic reproducing portion 14 are formed at one end portion of the slider 10 facing the magnetic disk D. An optical waveguide 15 is formed near the magnetic recording portion 13, and inside the optical waveguide 15, there is provided a near-field light generating element (not shown) that generates near-field light. On a mounting surface 10a on a rear surface side (opposite from the magnetic disk D) of the slider 10, terminals 17 and 18 for supplying power are each formed as a pattern.
The semiconductor laser element 40 has a semiconductor laminated film 42 which is formed on the substrate 41, and has an optical waveguide 46 which is formed in a shape of a stripe by a ridge portion 49 which is formed at an upper portion of the semiconductor laminated film 42. A first electrode 47 is formed on a bottom surface of the substrate 41, and a second electrode (not shown) is formed on an upper surface of the semiconductor laminated film 42.
The second electrode of the semiconductor laser element 40 is bonded, via a solder material 29, to a terminal surface 21b of a submount 21 where a terminal portion 22 is formed. A front surface 21a of the submount 21 that is perpendicular to the terminal surface 21b of the submount 21 is fixed to the mounting surface 10a of the slider 10 via a fixing member 19 such as an adhesive. At this time, an emission portion 46a of the optical waveguide 46 formed at a facet thereof is disposed to face the optical waveguide 15 of the slider 10.
The first electrode 47 is connected to the terminal 17 via a lead wire 7, and the terminal portion 22 is connected to the terminal 18 via a lead wire 8. Since the first electrode 47 and the terminal portion 22 are disposed to face the same direction (leftward direction in FIG. 14), the lead wires 7 and 8 are able to be connected easily.
When a voltage is applied between the first electrode 47 and the terminal portion 22, laser light is outputted through the emission portion 46a. The laser light outputted through the emission portion 46a is guided through the optical waveguide 15 of the slider 10 to reach the near-field light generating element, and causes the near-field light generating element to generate near-field light. The anisotropic magnetic field of the magnetic disk D is locally lowered due to heat from the near-field light outputted through the optical waveguide 15, and magnetic recording is performed on the magnetic disk D by the magnetic recording portion 13. As for data recorded on the magnetic disk D, it is read by the magnetic reproducing portion 14.
Heat generated in the semiconductor laser element 40 is transferred to the submount 21 via the solder material 29, to be then transferred to the slider 10 via the fixing member 19. Thereby, the heat generated in the semiconductor laser element 40 is dissipated through the submount 21 and the slider 10.
[Patent Literature 1] JP-A-2012-18747 (pages 7 to 22, FIG. 2)